Identification and characterization of biologically active secondary metabolites from Laurenciella sp.: a member of Laurencia complex (Ceramiales, Rhodophyta) from Brazil

Abstract

Marine algae have been evaluated as an attractive source of potential drugs in several biochemical and pharmacological investigations. Among seaweeds, the Rhodophyta Laurencia sensu lato, are known to be an extremely rich source of unique halogenated secondary metabolites, especially sesquiterpenes and acetogenins. Some Brazilian species of Laurencia have been reported to contain compounds with ecology activities such as antifeedant and antifouling, as well as pharmacological activities towards the trypanosome of Chagas' disease, leishmaniose and helminthiasis. However, most biological activity in Brazilian Laurencia complex species are reported from extracts and/or fractions, with relatively few concerning isolated compounds. In this context, Laurenciella sp., became a very attractive species from the complex, being a relatively unknown species that occurs only along the Brazilian southeastern coast and whose biological potential has never been investigated. This species was selected for investigation since preliminary studies undertaken during my Master's degree, on the species then called Laurencia intricata, showed lipophilic extracts to yield promising results in antimicrobial assay with pathogenic bacteria and fungi and also had interesting antioxidant effects. Knowing the genus Laurencia is an extremely rich source of secondary metabolites, and expecting the genus Laurenciella to provide predominantly the same two major biosynthetic groups of metabolites: sesquiterpenes and C15-acetogenins, we expect to find further new compounds with antimicrobial and antioxidant activities. This means there is a unique opportunity to isolate potentially new natural materials and investigate their biological activities. Results obtained will contribute directly to a better understanding of the natural products chemistry, pharmacology, taxonomy, and phylogeny of these algae. (AU)